Timer having an adjustable time interval



Oct. 24, 1967 G. A. DOTTO 9 I TIMBER HAVING AN ADJUSTABLE TIME INTERVAL Filed Feb. 14, 1966 2 Sheets-Sheet l INVENTOR GIANNI A. DOTTO rron/vs) Oct. 24, 1967 G. A. DOTTO 3,34

' TIMBER mvme AN ADJUSTABLE TIME INTERVAL Filed Feb, 14, 1966 2 SheetsSheet 2 INVENTOR GIANNI A. DOTTO ATTORNEY United States Patent Oilfice Filed Feb. 14, 1966, Ser. No. 526,985 7 Claims. (Cl. 200-38) The present invention relates to timers and more particularly to the means and methods for providing a timer having a means for selecting a desired time interval for advancing the control cams of said timer.

Present day timers of the type having a plurality of control cams mounted on a camshaft so as to be rotated thereby and a plurality of control switches operated by said cams are usually advanced through the program timing cycle by a mechanical escapement mechanism which is driven by a constant speed timer motor. The mechanical escapement mechanisms provide a snap-action rotational motion to the camshaft of the timer and, therefore, provide a snap-action making and breaking of the control switch contacts. Most mechanical escapement mechanisms have a cam or similar means for intermittently displacing a follower arm so as to store energy in a spring. When the cam releases the follower arm, the stored energy in the spring is released to rotate the camshaft of the timer.

One of the problems with escapement mechanisms as described above is that the time intervals for advancing the camshaft are fixed and cannot easily be changed. That is, the speed of rotation of the cam that displaces the follower arm determines the time interval and because the cam is driven by a motor having a constant speed, the speed of the cam cannot be easily changed.

Accordingly there is presented in this specification an improved escapement mechanism, or drive mechanism, that will permit adjustment of the time interval without changing the rotational speed of either the cam or the motor that drives the cam. The adjustment may be accomplished by incorporating a solenoid operated means for restraining the follower arm of the escapement in a displaced position so as to prevent the rotation of the camshaft of the timer. In addition, there are a plurality of switches for energizing the solenoid operated means at predetermined times, thereby releasing said follower arm so as to rotate said camshaft. Each of said switches is dis posed so as to be operated by an actuator which is carried by a rotating member which can be driven by the same motor which drives the cam. The location of the actuators on the rotating member and the selection of a particular switch determines when the follower arm will be released by the solenoid operated means and, consequently, determines the time interval for advancing the camshaft of the timer.

Other features of the present invention will become apparent as this specification increases.

It is an object of the present invention, therefore, to provide a timer having an adjustable time interval for advancing through the programmed timing cycle.

It is another object of the present invention to provide a novel and practical driving mechanism for a timer of the type having a plurality of cams mounted on a camshaft so as to be rotated thereby and a plurality of control switches operated by said cams.

It is a further object of the present invention to provide a means for changing the escapement time interval for advancing the camshaft of a timer without changing the rotational speed of the cam of said escapement or the motor that drives said escapement.

It is still another object of the present invention to provide a drive mechanism for a timer that utilizes a solenoid operated means for restraining the follower arm of an 3,349,199 Patented Oct. 24, 196'? escapement mechanism until said solenoid operated means is energized, thereby preventing the rotation of the camshaft of said timer for a predetermined time.

The present invention, in another of its aspects, relates to novel features of the instrumentalities described herein for teaching the principal object of the invention and to the novel principles employed in the instrumentalities whether or not these features and principles may be used in the said object and/ or in the said field.

Other objects of the invention and the nature thereof will become apparent from the following description considered in conjunction with the accompanying drawings and wherein like reference numbers describe elements of similar function therein and wherein the scope of the invention is determined rather from the dependent claims. For illustrative purposes, the invention will be described conjunction with the accompanying drawings in which: FIGURE 1 is an exploded perspective view of the timer of the present invention.

FIGURE 2 is a fragmentary top view of the timer of the present invention showing the follower arm of the escapement mechanism in its maximum displaced position.

FIGURE 3 is a fragmentary top view of the timer of the present invention showing the follower arm of the escapement mechanism in its lowest position permitted by the cam 17.

FIGURE 4 is an exploded perspective view of the cam and gear assembly of the escapement mechanism.

FIGURE 5 is a sectional view 55 taken from FIG- URE 3 to illustrate the operation of the solenoid and time interval selector switch contact members.

Generally speaking, the present invention is a timer comprising: a plurality of cams mounted on a camshaft so as to be rotated thereby; a plurality of control switches mounted so as to be operated by rotation of said cams; a driving means; an escapement mechanism for rotating said camshaft, said escapement mechanism having a cam for displacing a spring loaded follower arm; means for coupling said escapement mechanism to said driving means; solenoid operated means for restraining said follower afm in a displaced position, thereby preventing said escapement mechanism from rotating said camshaft; a rotating means having a plurality of switch actuators radially disposed thereon, said rotating means being coupled to and driven by said driving means; a plurality of switches for ene gizing said solenoid operated means at predetermined times so as to release said follower arm, thereby permitting said escapement mechanism to rotate said camshaft, each of said switches having a first contact member disposed so as to be contacted to a second contact member by an associated switch actuator; means for connecting a first contact member of each of said switches to said solenoid operated means; and means for selectively connecting a second contact member of said switches to a power source for said solenoid operated means, thereby establishing a time interval for advancing said camshaft.

Also, the present invention is a drive mechanism for a timer of the type having a plurality of control cams mounted on a camshaft so as to be rotated thereby, said mechanism comprising: a driving means; an escapement mechanism for rotating said camshaft, said escapement mechanism having a cam with a plurality of rise and fall contours for displacing a spring loaded follower arm; means for coupling said escapement mechanism to said driving means; solenoid operated means for restraining said follower arm in a displaced position, thereby preventing said escapement mechanism from rotating said camshaft; a plurality of switches for energizing said solenoid operated means at predetermined times so as to release said follower arm, thereby permitting said escapement mechanism to rotate said camshaft, each of said switches having a first contact member connected to said solenoid operated the following description.

means; means for selectively connecting a second contact member of said switches to a power source for said solenoid operated means, thereby establishing a time interval for advancing said camshaft; and means for intermittently operating said switches, said intermittent operating means being coupled to and driven by said driving means.

Referring now to the drawing, and particularly to the perspective view of FIGURE 1, the component parts of the present invention can be visualized in conjunction with The driving means for the timer is the timer motor which is fastened by means of the standoffs 11 and nuts 12 to the base plate 13. The support member 14 is also fastened to the base 13 by means of the standoffs 11. A pinion gear 34 on the output shaft of the timer motor 10 is engaged with the escapement gear 15 so as to rotate said gear at a constant speed. The pinion gear 34 is not shown in FIGURE 1. The gear 15 is mounted on the shaft 16 shown protruding through the support member 14. The cam 17 is also mounted about the shaft 16 so as to be rotated withthe gear 15. The details of the operation of the gear 15 and cam 17 will be discussed in conjunction with FIGURE 4.

There are three contact members 19, 20 and 21 fastened to the support member 14 by the rivets 18. The support member 14 is constructed of a suitable insulating material and has a suitable metallic contact area 46 on the side adjacent to the contact members 19, 20 and 2.1. The purpose of the metallic contact area will be discussed in conjunction with FIGURE 5. There are four contact member actuators 22, 23, 24 and 33 affixed to the top side of the gear 15 so as to operate the contact members 19, 20 and 21. (The actuator 33 is not shown in FIG- URE 1.)

The escapement mechanism of the timer drives the ratchet wheel 42 which rotates the camshaft 26 of the timer. (The ratchet wheel is not shown in FIGURE 1.) There are a plurality of control cams 28 mounted on the camshaft 26 so as to be rotated thereby. The control earns 28 operates the control switches 25 as the camshaft 26 is rotated. The terminal members 27 are connected to the various control switches 25.

The escapement spring 30 is wrapped around the standoff 11 and held in position by the tang 31 bent out of the base plate 13. The cam follower arm 32 which is associated with the spring 30 is partially shown in FIGURE 1. The plunger 29 of the solenoid 43 which acts to restrain the arm 32 is shown protruding through the plate 13. (The solenoid 43 is shown in FIGURE 5.)

Referring now to FIGURE 2, a top view of the timer of the present invention can be discussed.

The pinion gear 34 is engaged with the escapement gear 15. As stated previously, the escapement gear 15 and the cam 17 are mounted about the shaft 16. There is a rotating member 39 mounted about the shaft 16 so as to rotate with the gear 15. The cooperation of this member 39 and the cam 17 will be discussed in conjunction with FIGURE 4.

There is a roller on the follower arm 32 which follows the periphery of the cam 17. The follower arm 32 is pivotally connected to the drive arm 35 at the point 41. The drive arm 35 has a tip 37 which engages teeth on the ratchet wheel 42. There is a back-up pawl 36 aflixed to the plate 13 and engaged with the ratchet wheel 42 so as to prevent backward rotation of said wheel. There is a means 38 on the back-up pawl for guiding the tip 37 of the drive arm 35.

It can be seen that the follower arm 32 has been displaced to its maximum position by the rotation of the cam 17. The plunger 29 is located in a position so as to restrain the follower arm 29 in its displaced position. There is an electn'cal connection 44 between the aforementioned metaL lic conductor 46 on the support member 14 and the solenoid 43. (The solenoid 43 is not shown in FIGURE 2.)

Referring now to FIGURE 3, a view showing the follower arm 32 in the lowest position permitted by the cam- 17 can be discussed.

The follower 41 of the follower arm 32 is in the lowest position permitted by the rise and fall contour of the cam 17. It can be seen that the pin 17 is against the tang 39' on the periphery of the rotating member 39 farthest away from the follower 41. In FIGURE 2, where the follower arm 32 is in its maximum displaced position, the pin 17 is against the tang 39' which is closest to the follower 41.

Referring now to FIGURE 4, the arrangement of the gear 15, cam 16, and rotating member 39 can be discussed.

The bushing fits over the shaft 16 and is free to rotate thereon. The rotating member 39 is afiixed to the bushing 45 so as to be rotated thereby. The cam 17 is freely mounted on the bushing 45. The pins 17' protrude down through the tangs 39 of the rotating member 39. The gear 15 is affixed to the bushing 45 so as to impart rotation to said bushing when said gear is rotated by the timer motor 10. e

Referring now to FIGURE 5, the arrangement of the solenoid 43, contact members 19, 20 and 21, and actuators 22, 23, 24 and 33 can be discussed.

The solenoid 43 containing the plunger 29 is held to the base plate 13 by means of the bracket 47. The solenoid is connected to the metallic contact area 46 on the support member 14 and selectively through a power source to the three contact members 19, 20 and 21. The actuators 22, 23, 24 and 33 rotate with the gear 15 to raise the contact members 19, 20 and 21 against the metallic contact area 46.

With the above description of components in mind, and

by making reference to the drawing figures, the following analysis of operation will serve to convey the functional details of the present invention. Referring now to FIGURE 2, it can be seen that when the pinion gear 34 drives the escapement gear 15 in the direction of the arrow 48, the cam 17 which is driven with the gear 15 by the rotating member 39 causes the follower arm 32 to be deflected away from the cam 17 so as to store energy in the spring 30. As the cam 17 rotates farther and the roller 40 drops off the incline, the follower arm 32 is restrained by the plunger 29 of the solenoid 43. Since the cam 17 is free to turn with respect to the rotating member 39 except for the tangs 39 which act as stops for the pin 17', the cam 17 will rapidly rotate until the pin 17 is against the tang 39' which is farthest away from the roller 40 when said roller drops off the incline. In this manner, the problem of overthrow is eliminated. That is, when the roller 40 drops off, the energy in the spring 30 will not cause the cam 17 and gear 15 to rotate in the direction of the arrow 48.

The plunger 29 is normally up to restrain the follower arm 32 when it is deflected by the cam 17. Therefore, the only way that the follower arm 32 can be released is for the solenoid 43 to be energized to pull the plunger out of an interference position.

The solenoid 43 is energized when the selected contact member 19, 20 or 21 is contacted with the metallic contact area 46 on the bottom of the support member 14. If the contact member 21 is selected, the solenoid 43 will be energized each time that the follower arm 32 is displaced by the cam 17. That is, the contact member 21 is actuated by the actuators 22, 23, 24 and 33 which are located on the gear 15 so as to correspond to the location of the four lobes of the cam 17. This relationship is shown clearly in FIGURE 4. Similarly, it can be seen that if the contact member 20 is selected, the solenoid 43 will be energized every other time that the follower arm 32 is displaced, and if the contact 19 is selected, the solenoid 43 is energized every fourth time that the follower arm 32 is displaced.

Assuming that the gear 15 rotates one half revolution per minute, the contact member 21 will represent a 30 second time interval,the contact member 20 will repre- ,a camshaft so as to be rotated thereby;

sent a 60 second time interval, and the contact member 19 will represent a 120 second time interval.

Referring now to FIGURE 5, it can be seen that the spring 49 biases the plunger 29 so that it will restrain the follower arm 32 when the solenoid 43 is not energized. Therefore, the solenoid 43 only has to be energized for brief periods of time when an escapement action is required. Because of this feature, the solenoid 43 can be rather small and very reliable.

The action of the cam 17, spring 30, follower arm 32, and drive arm 35 in imparting a snap action rotational motion to the ratchet wheel 42 is well known in the escapement art. The present invention is an improvement over prior escapement mechanisms or drive mechanisms in that it readily permits the selection of a particular time interval for the advancement of the ratchet wheel. Although the illustrative embodiment shows three possible time interval selections, it is obvious that any combination can be obtained within the scope of the present invention.

The timer of the present invention, as hereinbefore described in one of its embodiments, is merely illustrative and not exhaustive in scope. Since many widely different embodiments of the invention may be made without departing from the scope thereof, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interposed as illustrative and not in a limiting sense.

What is claimed is:

1. A timer comprising: a plurality of cams mounted on a plurality of control switches mounted so as to be operated by rotation of said cams; a driving means; an escapement mechanism for rotating said camshaft, said escapement mechanism having a cam for displacing a spring loaded follower arm; means for coupling said escapement mechanism to said driving means; solenoid operated means for restraining said follower arm in a displaced position, thereby preventing said escapement mechanism from rotating said camshaft; a rotating means having a plurality of switch actuators radially disposed thereon, said rotating means being coupled to and driven by said driving means; a plurality of switches for energizing said solenoid operated means at predetermined times so as to release said follower arm, thereby permitting said escapement mechanism to rot-ate said camshaft, each of said switches having a first contact member disposed so as to be contacted to a second contact member operated by an associated switch actuator; means for connecting said first contact member of each of said switches to said solenoid operated means; and means for selectively connecting said second contact members of said switches to a power source for said solenoid operated means, thereby establishing a time interval for advancing said camshaft.

2. A timer as in claim 1 wherein said rotating means having a plurality of switch actuators disposed thereon is a gear, said gear being a means for coupling said escapement mechanism to said driving means.

3. A timer as in claim 1 wherein said cam has a plurality of rise and fall contours for displacing said follower arms, each of said rise and fall contours being associated with one of said switch actuators so as to displace said follower arm at a predetermined time before said solenoid operated means is energized.

4. A timer as in claim 1 wherein said solenoid operated means is a spring loaded plunger which restrains said follower arm when said solenoid operated means is not energized.

5. A drive mechanism for a timer of the type having a plurality of control cams mounted on a camshaft so as to be rotated thereby, said mechanism comprising: a driving means; an escapement mechanism for rotating said camshaft, said escapement mechanism having a cam with a plurality of rise and fall contours for displacing a spring loaded follower arm; means for coupling said escapement mechanism to said driving means; solenoid operated means for restraining said follower arm in a displaced position, thereby preventing said escapement mechanism from rotating said camshaft; a plurality of switches for energizing said solenoid operated means at predetermined times so as to release said follower arm, thereby per-mitting said escapement mechanism to rotate said camshaft, each of said switches having a first contact member connected to said solenoid operated means; means for selectively connecting said second contact members of said switches to a power source for said solenoid operated means, thereby establishing a time interval for advancing said camshaft; and means for intermittently operating said switches, said intermittent operating means being coupled to and driven by said driving means.

6. A drive mechanism as in claim 5 wherein said driving means is a motor having a constant speed rotational output.

7. A drive mechanism as in claim 5 wherein said cam has four rise and fall contours for displacing said follower arm and said means for intermittently operating a selected switch is a rotating member having four switch actuators radially disposed thereon, each of said switch actuators being disposed so as to operate an associated switch when one of said rise and fall contours displaces said follower arm.

BERNARD A. GILHEANY, Primary Examiner. 

5. A DRIVE MECHANISM FOR A TIMER OF THE TYPE HAVING A PLURALITY OF CONTROL CAMS MOUNTED ON A CAMSHAFT SO AS TO BE ROTATED THEREBY, SAID MECHANISM COMPRISING: A DRIVING MEANS; AN ESCAPEMENT MECHANISM FOR ROTATING SAID CAMSHAFT, SAID ESCAPEMENT MECHANISM HAVING A CAM WITH A PLURALITY OF CONTROL CAMS MOUNTED ON A CAMSHAFT SO AS LOADED FOLLOWER ARM; MEANS FOR COUPLING SAID ESCAPEMENT MECHANISM TO AND DRIVING MEANS; SOLENOID OPERATED MEANS FOR RESTRAINING SAID FOLLOWER ARM IN A DISPLACED POSITION, THEREBY PREVENTING SAID ESCAPEMENT MECHANISM FROM ROTATING SAID CAMSHAFT; A PLURALITY OF SWITCHES FOR ENERGIZING SAID SOLENOID OPERATED MEANS AT PREDETERMINED TIMES SO AS TO RELEASE SAID FOLLOWER ARM THEREBY PERMITTING SAID ESCAPEMENT MECHANISM TO ROTATE SAID CAMSHAFT, EACH OF SAID SWITCHES HAVING A FIRST CONTACT MEMBER CONNECTED TO SAID SOLENOID OPERATED MEANS; MEANS FOR SELECTIVELY CONNECTING SAID SECOND CONTACT MEMBERS OF SAID SWITCHES TO A POWER SOURCE FOR SAID SOLENOID OPERATED MEANS, THEREBY ESTABLISHING A TIME INTERVAL FOR ADVANCING SAID CAMSHAFT; AND MEANS FOR INTERMITTENTLY OPERATING SAID SWITCHES, SAID INTERMITTENT OPERATING MEANS BEING COUPLED TO AND DRIVEN BY SAID DRIVING MEANS. 